Dose numbers for oral formulations are not comparable to injectable ones — a second dataset

The SOUL trial: cardiovascular outcomes trial for oral semaglutide in people with type 2 diabetes and cardiovascular disease or chronic kidney disease. It demonstrates that benefit appears to be a property of the molecule and exposure, not specific to the route.

Someone should write this up properly, and it should probably not be me.

This follows post #14 rather than contradicting it.

SNAC is the sodium N-(8-[2-hydroxybenzoyl]amino) caprylate, an absorption enhancer that transiently raises local pH in the stomach and promotes gastric mucosal absorption. Without it, oral bioavailability of semaglutide would be too low for clinically useful dosing.

Worth separating two things that post #16 runs together.

Research-use-only oral material is not a licensed tablet and there is no reason to assume it carries a functioning absorption-enhancement system at all. The formulation is most of the product here.

On variability: the between-person spread in exposure for oral semaglutide is wide enough that two people on the same dose can have quite different plasma concentrations. That is inherent to the absorption route.

Not the whole picture, but the part of it I can speak to.

Everything in post #16 holds. The case it does not cover is the one I have.

PIONEER programme is phase 3 for oral semaglutide. The trials cover multiple indications and durations. Reading them requires attention to which trial is which because they are not all the same question.

Speaking for myself and not for anyone else who has posted here.

Good question, well framed, and I would like to see it answered properly.

Taking the oral product with more water than instructed reduces absorption rather than helping it. That is counter-intuitive and it is one of the few dosing instructions in this field with a clear pharmacokinetic basis.

I would put this at better than even and not much better.

Picking up post #23: that is the part I would want checked first.

Timing consistency matters more for oral dosing than for weekly injection, because absorption depends on the state of the stomach and the state of the stomach varies through the day.

I had written a reply contradicting post #23 and deleted it. Here is what survived.

Why administration conditions matter for oral semaglutide and not for injectables: the oral formulation depends on a transient pH effect in the stomach. Anything that changes gastric pH or transit time changes absorption. Food does both.

The gastrointestinal tolerability profile of the oral formulation is broadly similar in character to the injectable, which supports the effects being systemic rather than local irritation.

The uncertainty is in the assumption, not in the calculation.

Why an oral formulation is a formulation achievement: the molecule is the same but the tablet is novel. Getting a peptide across the gastric epithelium at usable bioavailability is a chemistry problem, not a dose problem.

I would put a moderate confidence on that and no more.

PIONEER 6 was a cardiovascular safety trial for oral semaglutide, not an efficacy trial. Non-inferiority for safety was demonstrated. The point estimates favoured the drug but the trial was not designed to establish benefit.

I checked the source rather than the summary, and they differ.

Post #28 is the version of this I will quote in future. One addition.

The absorption enhancer in the licensed oral product works by transiently raising local gastric pH and promoting absorption across the mucosa. It is the reason the fasting and water-volume instructions are specific rather than cautious.